This invention relates generally to a color image sensor, and more particularly to a color image sensor in use with a color image scanner, for example.
FIG. 1 shows a perspective view schematically illustrating a major part of a color image sensor 1 of the prior art.
The color image sensor 1 is a linear image sensor made up of solid-state image pick-up elements such as CCD. As shown, a plurality of optical sensors 2 are linearly arrayed at predetermined pitches P in the main scanning direction. Each optical sensor 2 reads the image information of one pixel, and is comprised of an optical sensor (R sensor) 3 for reading the red component of the color components contained in the image information, an optical sensor (G sensor) 4 for reading the green component, and an optical sensor (B sensor) 5 for reading the blue component.
On the other hand, a black and white image sensor 6 contains a plurality of optical sensors 7 each for picking up the image information contained in one pixel, as shown by a one-dot-chain line in FIG. 1. These sensors 7 are linearly arrayed at predetermined pitches P in the main scanning direction.
In the prior color image sensor 1 as mentioned above, to read the image information of one pixel, i.e., the color components of one picture element, three types of optical sensors, the R sensor 3, the G sensor 4, and B sensor 5 are required. Therefore, the structure of the color image sensor is more complicated than the black and white image sensor. This makes it difficult to manufacture the color image sensors, resulting in the increased cost to manufacture.